Remember the stigma readers faced with the so-called bodice rippers. Well, now there is embarrassment for those who read erotic books, so it could be readers feel safer reading them on an e-reader. Writers often use a fictitious name to write them because of the stigma.
Sex is a part of life, so it's hard for me to understand why there is still this stigmatism around the subject. As to whether there is more sex in e-books than prints I don't know, but it is an interesting question.
What do you think?